None.
The present invention relates to computer driven printers and, more particularly, to an improved print media cutter. For ease of reference, instead of the term xe2x80x9cprint mediaxe2x80x9d, the term paper will be frequently used herein and is intended to encompass all forms of print media including paper, transparencies, vellum, etc.
The media cutter assembly of the present invention is primarily designed for large scale printers/plotters which receive print media from a roll supply. After printing of a sheet of media from the roll, a clean transverse cut needs to be made without wrinkling of the media and with a minimum of paper positioning or repositioning to cut the printed sheet and, if necessary, the leading edge of the roll may be further trimmed. A variety of prior art cutting mechanisms have been used including stationary full length linear blades in conjunction with moveable rotary cutting blades mounted on a cutter carriage which in turn moves on cutter carriage support rods or guide tracks separate from the printhead carriage and its support rods or tracks. Both manual and automatic systems have been used including the type disclosed in U.S. Pat. No. 5,296,872 issued Mar. 22, 1994 to Caamano and owned by the assignee of the present invention. In this patent a separate cutter carriage is connected, when desired, to the print head carriage for movement therewith and is disconnected from the print head carriage after the cutting operation.
It is the primary object of the present invention to provide a reliable media cutter assembly which is rigidly connected at all times to the print head carriage so that separate print head and cutter carriages and associated guide structure for each are unnecessary.
The present invention provides a media cutter assembly for attachment to a moveable printhead carriage of a computer driven printer comprising:
a) a cutter wheel support member having a media cutter wheel mounted thereon for rotation about an axis, said support member also including a first cam element;
b) a cam element carrier and cutter actuator moveable generally transversely to said cutter wheel axis, said carrier having a second cam element thereon engaged by said first cam element and said actuator being engageable with cutter actuation means on said printer;
c) a housing having first guide means therein for guiding said cutter wheel support member in a path of movement to move said cutter wheel between inactive and active positions relative to said housing, said housing having second guide means for guiding said cam element carrier relative to said housing in a path of movement generally transverse to said path of movement of said cutter wheel between a cutter inactive position and a cutter active position; and
d) means for biasing said cutter wheel support member for movement of said cutter wheel toward said active position relative to said housing.
The present invention further provides a printer having a moveable printhead carriage and a print media cutter assembly attached thereto, said media cutter assembly comprising:
a) a cutter wheel support member having a media cutter wheel mounted thereon for rotation about an axis, said support member also including a first cam element;
b) a cam element carrier and cutter actuator moveable generally transversely to said cutter wheel axis, said carrier having a second cam element thereon engaged by said first cam element and said actuator being engageable with cutter actuation means on said printer;
c) a housing having first guide means therein for guiding said cutter wheel support member in a path of movement to move said cutter wheel between inactive and active positions relative to said housing, said housing having second guide means for guiding said cam element carrier relative to said housing in a path of movement generally transverse to said path of movement of said cutter wheel between a cutter inactive position and a cutter active position; and
d) means for biasing said cutter wheel support member for movement of said cutter wheel toward said active position relative to said housing;
said printer having an output platen and a stationary elongated cutter bar in a cutter wheel receiving channel which extends transverse to the path of movement of printed media to be cut, said cutter wheel in said cutter active position being engageable with said cutter bar.
The invention further provides a method of cutting printed media sheets in a printer from a rollfeed supply of media comprising the steps of:
a) moving the printed media in a forward direction across a stationary cutter bar which extends transversely to the direction of movement of the media and then holding said media in a stationary position across said cutter bar;
b) using a printhead carriage having an attached cutter assembly to move said cutter assembly in a first direction to a position at a first side of said media to engage means on said cutter assembly with printer structure at said first side of said media;
c) moving said cutter assembly and printhead carriage in a second direction to first move a cutter blade from an inoperative position to an operative position and subsequently engaging said cutter blade with said cutter bar as said cutter assembly moves from said first side of said media to a second side of said media to cut said media; and
d) returning said cutter assembly and printhead carriage in said first direction to said first side of said media while said cutter blade remains engaged with said cutter bar and then moving said cutter blade to said inoperative position.